A device of this type is known e.g. from EP 1 134 182. It is an automated filling device which fills food products like for example dairy products into beakers or bottles. Thus, the support elements also designated as cell plates run through the device in an endless manner while being supported at a chain. Typically the operating stations which sterilize, dry, fill and close the containers are arranged along the upper main element. Through a first lateral element, the support elements then run into the lower main element arranged below the upper main element and are fed again to the upper main element through a second lateral element.
In most of the filling devices currently available in the market, the number of containers filled depends on the processing time of the slowest operating station of the chain. The chain feed is provided in a timed manner so that in a simple version, always those containers are treated which are jointly supported on a support element. However, there are also so-called double step devices in which the containers of two support elements are simultaneously treated at the operating stations.
The chain drive technique is tried and tested and has been used reliably for a long time though it has substantial disadvantages. Initially there is the basic problem that the chain elongates during operations. Consequently, the distance measured in feed direction between the support elements and thus also between the containers supported by the support elements increases over time. This is problematic since dosing sterilization agents, blowing in drying air, filling the containers and also closing at particular operating stations requires a comparatively exact positioning of the containers. Consequently, centering devices are required for chain operated devices.
The support elements are pulled through the device on sliding rails; furthermore a support that is approximately central in feed direction is required above a certain size of the support elements. The mass inertias that have to be overcome in combination with the movement velocities of the support elements through the device require strong and thus heavy chains. The drive wheels and motors are also sized accordingly. Thus, a device of this type includes very massive and heavy components.
For quite a while, persons skilled in the art have discussed how to design a chainless drive for a device of this type. In this context, for example, the German utility model DE 210 79 U1 has been published. Herein, a lantern pinion teething is shown which directly engages the support elements and pushes the support elements through the device. Thus the lateral elements are configured as arcuate rail systems connecting the upper main element and the lower main element. The support elements are provided with spacers for moving through the lateral elements.
From EP 1 495 A1 additional drive concepts are known through which the support elements, cell plate adjoining cell plate, can be pushed through a device of this type. Among other things, a worm drive conveyor is proposed in this context.
Pushing the cell plates through the device has the essential advantage that a chain which has elongation problems can be omitted. As a matter of principle however, there remains the problem that excessive friction forces have to be overcome and typically a support that is central in feed direction is still required for the cell plates. Furthermore, also when pushing the cell plates through the device it is not assured that the distances of the support elements or containers in feed direction are constant. As a matter of principle there is the risk that contaminating particles collecting between the support elements, for example production residues, can add up to form considerable total deviations.
Also though EP 1 495 997 A1 proposes for friction minimization to push the cell plates through the device on rollers, besides the recited summation errors, the problem remains that the support proposed for the cell plates therein cannot be used in the machine for filling bottles. Bottles are typically supported at the bottleneck when moved through the filling device. Thus, the support elements are approximately cut in halves along a row of container receivers. For inserting the bottles, the support element halves are lifted and are moved apart parallel to the feed direction. The bottle is typically inserted from above into the opening thus widened. Subsequent thereto, the support element halves are moved back into their starting positions and enclose the bottle neck.
Besides the fact that splitting the support elements into support element halves augments the problem of summation errors and thus the problem of exact alignment of the support elements under the operating stations, EP 1 495 997 A1 does not permit the predescribed opening of the cell plates for inserting the bottles.